LeetCode:68.寻找两个正序数组的中位数

目录

1.寻找两个正序数组的中位数

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1.寻找两个正序数组的中位数

class Solution {
public:
    int getMinKth(vector<int>& nums1, vector<int>& nums2, int k)
    {
        int m = nums1.size(), n = nums2.size();
        int index1 = 0, index2 = 0;

        while(true)
        {
            if(index1 == m) return nums2[index2 + k - 1];
            if(index2 == n) return nums1[index1 + k - 1];
            if(k == 1) return min(nums1[index1], nums2[index2]);

            int newIndex1 = min(index1 + k / 2 - 1, m - 1);
            int newIndex2 = min(index2 + k / 2 - 1, n - 1);
            int sum1 = nums1[newIndex1];
            int sum2 = nums2[newIndex2];

            if(sum1 <= sum2)
            {
                k -= newIndex1 - index1 + 1;
                index1 = newIndex1 + 1;
            }
            else
            {
                k -= newIndex2 - index2 + 1;
                index2 = newIndex2 + 1;
            }
        }
    }

    double findMedianSortedArrays(vector<int>& nums1, vector<int>& nums2) 
    {
        int length = nums1.size() + nums2.size();
        if(length % 2 == 1)
            return getMinKth(nums1, nums2, (length + 1) / 2);
        else
            return (getMinKth(nums1, nums2, length / 2) + getMinKth(nums1, nums2, length / 2 + 1)) / 2.0;
    }
};